function  y = overTimePlot(tData)
%UNTITLED2 Summary of this function goes here
%   Detailed explanation goes here 
   global tData;
   tData = readOverTime();
   hold on;
   dSize = size(tData);
   len = dSize(1)/2;
   seller = [];
   price = [];
   itemId = [];
    y = [];
   for i = 1 : len
       seller = [seller,tData(2*i - 1,1)];
       price = [price,tData(2*i - 1,2)];
       itemId  = [itemId,tData(2*i - 1,3)];
       y = [y;tData(2*i,:)];
   end
   y = y';
   bar(1:31,y,'stacked');
   lg = [];
   for i = 1:len
       s = strcat(num2str(seller(i)),'--');
       s = strcat(s,num2str(price(i)));
       s = strcat(s,'--');
       s = strcat(s,num2str(itemId(i)));
       lg = strvcat(lg,s);
   end
   %lg = lg(1,1:length(lg)-1);
   %display(lg);
   legend(lg);
   
   function ret = readOverTime()
      ret = textread('overTime.txt');
      ret = ret(:,1:31);
    end
end

